161251510004 has 24 divisors (see below), whose sum is σ = 306905968488. Its totient is φ = 73686902400.

The previous prime is 161251509973. The next prime is 161251510027. The reversal of 161251510004 is 400015152161.

It can be written as a sum of positive squares in 4 ways, for example, as 95884361104 + 65367148900 = 309652^2 + 255670^2 .

It is a super-2 number, since 2×161251510004² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15346187 + ... + 15356690.

It is an arithmetic number, because the mean of its divisors is an integer number (12787748687).

Almost surely, 2^161251510004 is an apocalyptic number.

It is an amenable number.

161251510004 is a deficient number, since it is larger than the sum of its proper divisors (145654458484).

161251510004 is a wasteful number, since it uses less digits than its factorization.

161251510004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30702995 (or 30702993 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 26.

Adding to 161251510004 its reverse (400015152161), we get a palindrome (561266662165).

The spelling of 161251510004 in words is "one hundred sixty-one billion, two hundred fifty-one million, five hundred ten thousand, four".